The invention relates to a linear output amplifier for charge coupled devices.
Charge coupled devices (CCDs) are of significance for the processing of analog signals as they can be used as analog shift registers. The conventional output circuits of CCDs are constructed as source followers, where the non-linear characteristic curve of the MOS-source follower is largely linearized with an external load resistance with the aid of a highly ohmic source resistance. The published article by D. F. Barbe "Imaging Devices Using the Charge Coupled Concept" in the Proceedings of the IEEE, Vol. 63, No. 1 Jan., 1975, pages 38 to 67, describes such an output circuit. However, the highly ohmic source resistance of this arrangement has the disadvantage that the upper cut-off frequency of the output circuit is considerably reduced. A further disadvantage lies in the fact that the amplification of such a source follower is always less than 1.